Process and apparatus for the production of television images



Aug 27 1935- H. CUNNINGHAM 2,012,270

PROCESS AND APPARATUS FOR THE PRODUCTION OF TELEVISION IMAGES Filed Dec. 8, 1931 ITI/vento @P7 @A i ,latented Aug. 27, 1935 e A y PROCESS AND APPARATUS FOR THE PO- k DUCTION OFV TELEVISION IMAGES Henry Cunningham, Cleveland, Ohio Applicatinnnecember s, 1931, serial No. 579,823 In Germany December 8, 1930l V`13 Claims. (Cl. USV- 6) A In television, it has been `customary heretofore lln or thin layer of liquid electrolyte, the other to receive a visual-image as formed by the optielectrode paired against the multitude of eleccallmpressionrproduced by a varying light, as trode-'points in the iield being at the side or viewed by aid of rapidly moving openings. Nec'- about the. area so provided.V Depending upon the essarily with such an arrangement, a fundaf electrolytic materials andthe particular reac- 5 mental-handicapis introduced in thatthe illumitions produced, picture-image eiects in black nationv is limitedgat best, and such usage is re- 'and white or incolormay be had. stricted to smallldirectaviewedkinstallations. In By `way of illustration, the accompanying accordance with rthe present invention (for'which drawingr indicates the principle of thev invention,

I have filed an-'application in Germany, Decemsuch showing beinglin simple'terms forready 10 tro-chemical A change. Suchl electro-chemical apparatus illustrative oi' the vprinciple of the4 change may be provided in areceiving field made invention.

ber 8tl1,l19 30), limitations of a primary variable comprehension. Y Y y light are avoided, and picture images may be re- Insuch drawingzk .l f Y 1 Y Acelved 1n termsof contrast as produced by elec- The sole figure is al diagrammatic showingof up of a multitude of po1nts,each concerned in an v In said .figure of the drawing there is shown a electrolyticY change producing contrasts ofv light scanning dis-c 2 having holes 3 arranged inspiral and shade in the receiving eld of the'gpicture rows, the discfbeing driven by an electric motorf corresponding to thesimilar lights and shades in so as torapi'dly sweepfthe openings 3 across the the" original neldrof vision Yat the transmitter. line of sieht between ari Objectif Ito be viewed-and 2o "In the receiving neld, the points'may be smallor a photo-electric cell E, asuitable cabinetv or cas'- large, depending, upon Y the sizev of the installaing enClOSinSthe Same." The Object t0 be Viewed, tion desired, and the manner of application, and while here indicated as a simple geometric ligure,

the manner of viewing. For instance, with a Will 0f COUISeIl praetee befahl fleldef VSOl small installation for direct viewing at close whichit is desired to transmit. The photof-elec-y 25 range, theVV points in the receiving eld may be tric cell 6 is` connected byfwires l, 8, to an am: small andv closely spaced,` such as on the order Plifle eompfsingthermionic tubes 9, and being of 60 .per inch, being thus comparable tothe light coupled by resistaces and ccndensers in. any

'Y r ,and dark points in certain photo-engraving imusual or preferred circuit-arrangement, the out.-v

ages. For installations for direct viewing but at 'plltl'Om the last the'rlome'tube 0lV VelVe.9 DTO- 30 a'greater distance, the points may be for instance eeeding t0 the Winding H3 of,a^transf0rmer.whose of 4a size andspacing oi 8 or fewer per inch. winding Hisl inratio topreferablygive a step- Again, where,'instead of direct viewing, the picdownin voltage ,and an increase in ampelagetureimage as formed'is'reiiected andprojected FIOm ii-he Winding-V. l l, Wire AConnections l2 may in themanner cfa stereopticon-projection upon lead for wire-transmission directly ,to the input 35 a, viewingescreen, the deiining points in the rel leads' I3 at .the receiver. station; or for radio', the

.ceiving neld may be quitezsmallgor larger, `def Y Output of connections vl2 may be ampled and pending upon thefocaldistanceoftherpick-up. Am0dllllaeilr 0111501. a carrier wave, and Athence be .f The v.points as yreferred te` in the receiving field broadcast. Infthisjfa plurality 'of electrodes, I4

are in eirect individual electrodes, which receive are arranged closely Ona backing or support l5 40 thecurrent as distributed and synchronized in 0f insulating Irlatelal,VY the electrodes being in accordance withlthe-transmitter, the synchroni'- lines corresponding tothe path followed bytheVV Azation being accomplished byV any suitable orl scanning-openings in their traverse across the l preferred means. f Again, thertransmission mayv original viewing field; vthat is, to the extentthat .15 be by radio or by wire,as desired in any particuthe paths of the scanning-openings are somewhat 45 lar instance. The electrodes `constituting the arcuate, correspondingly therows of the elecplurality of controlled points in the receiving trodes Ill in the receiver will be of similar'arcuiieldgmay be of a' material directly 'contributing ate arrangement. Each of the electrodes Mare to the reactionfor in some instances ofamatef exposedina bath supplying the reagents to be v rialvnon-reactive, and merely introducing the involved'in'the reaction., Another general elec- 50 currentto alocus where reaction may be circumktrede i6 is provided, for instance in the formv of scribed to the area concerned. Conveniently, anarrow strip spaced from and insulatedv from 4such a'receiving eldmay be mounted such that the general bank of electrodes which areon the the multitude' of point electrodesare' carried in back-wall. A glassiace or cover-plate I'l suitably 53 an insulating base allowing the application of a mounted may provide an unobstructed'closure for 55 the bath. Each of the electrodes M may be connected to a corresponding commutator-segment on a commutator I8 driven by electric motor i9 in synchronism with the transmitting motor il,

the circuit being completed through the coinmubeing used at the receiving electrodes "may be;

controlled. A positive or a negative image may be had in accordance with polarity of connections in the transmitter or the number of stages of amplification. VWhere the current as received by the input line I3 is too weak to satisfactorily operate the electrolytic action, a local amplifier current, battery or otherwise, may be provided in the circuit, ^23, Z4. e

Depending upon the electrolyticmaterials and the particular reaction produced, picture-image effects in black and white or in color may be had. For example, the electrodes i4 may be of metallic silver, and with a thin layer ofl liquid thereover composed ofY a silvernitrate solution about l per cent, acid-ined with nitric acid about 1 per cent. On supply of electric current in synchronization and distribution to the electrode-field, l those points receiving current impulseswill correspondingly become black from formation of silver peroxide, While others remain white, forming the contrasting lights and shades in consonance with the transmission eld of vision. Instead of silver,

other metals, as lead,copper, etc., may be employed for the electrode material. According as the current impulses vare stronger or weaker', the darkening on the electrode points may be from brown or grey to black. Or, the electrode points l4'may be of non-reactive material, such as num and the liquid layer thereover may be an ionizable salt solution, such as sodium sulphate about 4 per cent with a few drops of a l percent solution of phenol-phthalein. With the synchronized distribution of electric current, certain of the points will show red while others remain white, thus providing the contrast of light and shade in accordance with the original image-field.

With non-reactive electrodes Vand an ionizable salt solution,Y or acid oralkali, and an indicator such as methyl orange'in the liquid layer over the electrodes.corresponding color contrasts may be had. In all these cases, the coloration is synchronized with the electric impulse, and passes therewith, the speed-rate being such that the persistence in the eye of a person viewing the receiving screen will give the eiTect of a complete image representation, as Well understood in thetelevision art. i,

By providing receiving-elds operating in two or more colors, each eld having its own color as synchronized with the light and shade of the original transmission, and by then reflecting these fields in superposition' upon a viewing-screen, pictures in natural .colors may be had. Similarly, the image eld as produced by any receiver may be reflected and projected in enlargement upon a viewing-screen in proportions as may be desired. Thustheinvention affords a versatility in size and usagev accommodation, in black and white, in plain color or in combination colors as in any instance desired. And by having an acid or self-clearing agent initially present, the elecplativ tro-chemical action at a given point is evanescent, that is it ceases on cessation of the current-flow and the change in appearance at that point produced by the current is promptly effaced and the primarily clear or colorless state restored. Highly rapid picture-change effects accordingly can be had, as not possible otherwise.

Other modes of applying the principle of my invention may be lenfiployed instead` of the one eX- plained, change being made as regards the means and the steps herein disclosed, provided those ,Stated in any of the following claims, or their equivalent be employed.

VI'therefore particularly point out and distinctly claim as my invention:-

1.. A process for producing television pictures in which of a plurality of points in the picturefield some appear as light points and others as dark points to make up the lights and shades of the picture on a clear chemical ground, said process comprisingappropriately inciting evanescent velectro-chemical change atl various points in the visual held corresponding to electric currents from like points in the original, and clearing such electro-chemical change on current cessation, by a chemical agent initially present. y

2.7Av process in'accordance with claim 1, comprising inciting, the electro-chemical action in colors which disappear Vwith cessation of the currents.

3. A process in accordance Withclaim 1, comprising inciting-the" electro-chemical actionV in contrasting colors'. y Y

4. A vprocess forproducing television pictures in which of a plurality of points in the picturefield some appear as light points and others as dark pointsv to make up the lights and shades of 'the picture, said process comprising appropriately inciting electro-'chemical change at variouspoints in a pluralityA of visual fields corresponding to electric currents from like points in the original, such electro-chemical Vchange being in different colors in the different visual fields, and'combining the color effectsinjanother visual field in common to produce a picture in natural color effect.

5. A process for producing television pictures in'vvhich of a plurality of points inthe pictureneld some appear as light points and others as dark points to make up the lights and shades of the picture, said process comprising appropriately inciting electro-chemical action at various points in the visual field corresponding to electric currents from like points in the original, and reiiecting the so-produced picture upon another viewing-screen. 1.

6. Aprocessfor producing television pictures in which of a plurality of points in the pictureeld some ,appear as light points and others Vas dark pointsv to makeup the lights and'shades of the picture, said process comprising appropriately inciting electro-chemical actionV at various points l h V8. Television apparatus comprising a screenv composed of a plurality vof metal electrodes banked together and insulated from each other, a self -clearing chemical reactant in common, and

a circuit-completing electrode in common.l

9. Television apparatus comprising a screen composed of'a plurality of electrolytic electrodes; a self-clearing chemical reactant thereover in common, and a Ytransmitting means to impress electric currents variously upon the different electrodes in accordance With excitations at corresponding points in the original visual-eld.

` l0. Television apparatus, composed ci a plurality of electrolytic electrodes, a chemical reactant thereover in common, and a transmitter including a light-scanning means and current-transfer means. v

1l. Television apparatus, comprising a screen composed of a pluralityof electrolytic electrodes, a chemical reactant thereover in common, a transmitter including a scanning-means, and a motor for driving the same. Y

12. Television apparatus, comprising a screen composed of a plurality of electrolytic electrodes comprising a screen banked together andr insulated separately, a chemical reactant thereover in common, a plurality of Wires leading to such electrodes, a commutator controlling said Wires, a motor for driving said commutator, and a transmitter including a light-scanning means operated in synchronism with the said commutator driving motor.

13. Television apparatus, comprising a screen composed of a plurality of electrolytic electrodes banked together and insulated separately, a chemical reactant thereover in common, a plurality of Wires leading to such electrodes, a commutator controlling said wires, a motor forjdriving said commutator, a transmitter including a scanningmeans, and a motor for driving the same in synchronism With the said commutator-driving mo tor.

HENRY CUNNINGHAM. 

